Ab initio calculation of differential cross sections for the double ionization of water vapour by electron impact

• Published in: Journal of physics. B, Atomic, molecular, and optical physics Vol. 42; no. 2; pp. 025201 - 025201 (9)
• Main Authors: Kada, I, Mansouri, A, Dal Cappello, C, Hervieux, P A, Roy, A C
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 28.01.2009; Institute of Physics
• Subjects: Ab initio calculations; Atomic and molecular collision processes and interactions; Atomic and molecular physics; Calculations and mathematical techniques in atomic and molecular physics (excluding electron correlation calculations); Electron scattering; Electronic structure of atoms, molecules and their ions: theory; Exact sciences and technology; Molecular excitation and ionization by electron impact; Physics; Water; Inorganic compounds; Numerical integration; Electron impact ionization; Multiple ionization; Differential cross sections; Theoretical study; Wave functions; Ab initio calculations; Electron-molecule collisions; Triatomic molecule
• ISSN: 0953-4075; 1361-6455; 1361-6455
• DOI: 10.1088/0953-4075/42/2/025201

We carry out a theoretical analysis of the double ionization of the water molecule by fast electrons. The analysis is based on a perturbative approach. For the final state we employ the well-known 3C wavefunction which has the correct asymptotic behaviour when all interparticle distances are large. The initial state of the target is described by an accurate molecular wavefunction proposed by Moccia (1964 J. Chem. Phys. A 40 2186). We present five-fold differential cross sections for a wide variety of kinematical conditions. We show that a simple summation over four indices is able to avoid a time-consuming triple numerical integration required to take account of the orientation of the molecule in space. The mechanisms of the double ionization of the water molecule are identified and discussed.